Switching device, generator-motor apparatus using switching device, drive system including generator-motor apparatus, and computer-readable recording medium on which a program for directing computer to perform control of generator-motor apparatus is recorded

ABSTRACT

A generator-motor apparatus ( 100 ) includes a control circuit ( 20 ), an alternator ( 50 ), electrode plates ( 83, 84 ), and switching devices (SW 1  to SW 6 ). The electrodes plates ( 83, 5 84 ) have a substantial horseshoe shape, and are provided on an end surface of the alternator ( 50 ) so as to surround a rotating shaft ( 50 A) of the alternator ( 50 ). Each of the switching devices (SW 1  to SW 6 ) is formed by sandwiching a MOS transistor between two electrodes, and has a can structure for sealing the internal space of the switching device using a resin. The switching devices (SW 1,  SW 3,  SW 5 ) are directly attached to the electrode plate ( 83 ) by means of soldering, and the switching devices (SW 2,  SW 4,  SW 6 ) are directly attached to the electrode plate ( 84 ) by means of soldering. The control circuit (2% controls the switching devices (SW 1  to SW 6 ). The switching devices (SW 1  to SW 6 ) drive the alternator ( 50 ) as an electric motor or an electric power generator.

FIELD OF THE INVENTION

The invention relates to a generator-motor apparatus having goodmountability, a switching device used for the generator-motor apparatus,a drive system including the generator-motor apparatus, and acomputer-readable recording medium on which a program for directing acomputer to perform control of the generator-motor apparatus isrecorded.

BACKGROUND OF THE INVENTION

Japanese Patent Laid-Open Publication No. JP-A-07-184361 discloses avehicular generator-motor apparatus having both the function as athree-phase motor for starting an engine mounted in a vehicle and thefunction as a three-phase alternating current generator for charging abattery.

The above-mentioned vehicular generator-motor apparatus includes amotor-generator and an integrated rectifier. The motor-generatorincludes a magnetic rotor, a stator core, and a three-phase armaturewinding. The stator core is fixed to a housing of the motor-generator.The three-phase armature winding is winded around the stator core. Themagnetic rotor rotates inside the perimeter of the three-phase armaturewinding winded around the stator core.

The integrated rectifier is fixed to an inner surface of a rear housingof the motor-generator. The integrated rectifier includes six MOS powertransistors arranged on a silicon (Si) substrate.

The integrated rectifier controls an electric current supplied to thethree-phase armature winding by performing switching control of the sixMOS power transistors, thereby directing the motor-generator to serve asan electric motor. The integrated rectifier also converts an alternatingvoltage generated by the motor-generator using engine torque into adirect-current voltage, thereby directing the motor-generator to serveas an electric power generator.

The vehicular generator-motor apparatus is a motor-generator having theintegrated rectifier for controlling driving of the motor generatorprovided on the end surface thereof.

The above-mentioned vehicular generator-motor apparatus, however, is notconfigured with consideration given to cooling of the MOS powertransistors constituting the integrated rectifier. This leads toproblems. For example, improving the heat resistance of the MOS powertransistors leads to an increase in size of the integrated rectifier,resulting in deterioration of the mountability of the vehiculargenerator-motor apparatus.

Also, providing the integrated rectifier separately from themotor-generator leads to an increase in the number of wiring harnesses,resulting in deterioration of the mountability of the vehiculargenerator-motor apparatus.

DISCLOSURE OF THE INVENTION

It is an object of the invention to provide a generator-motor apparatushaving good mountability.

It is another object of the invention to provide a switching device usedfor the generator-motor apparatus having good mountability.

It is still another object of the invention to provide a drive systemincluding the generator-motor apparatus having good mountability.

It is yet another object of the invention to provide a computer-readablerecording medium on which a program for directing a computer to performcontrol of the generator-motor apparatus having good mountability isrecorded.

A first aspect of the invention relates to a switching device includinga first electrode, a second electrode, a switching element and a sealingmember. The switching element is electrically connected to the firstelectrode and the second electrode, and sandwiched between the firstelectrode and the second electrode. The sealing member is providedaround the switching element, and contacts the first electrode and thesecond electrode.

In the switching device, the switching element is sandwiched between thetwo electrodes. The two electrodes dissipate heat generated by theswitching element.

Accordingly, with the switching device, the switching element can beefficiently cooled. Preferably, the switching element is electricallyconnected to the first electrode and the second electrode by means ofsoldering.

Therefore, the step of wire bonding can be omitted, enabling improvementin productivity.

The switching element is preferably an N channel MOS transistor. In thiscase, the reverse polarity structure of the MOS transistor can be easilyrealized.

A second aspect of the invention relates to a generator-motor apparatusincluding a motor, a first electrode plate, a second electrode plate,and a multi-phase switching element group. The motor includes a rotorand a stator, and serves as an electric power generator and an electricmotor. The first electrode plate and the second electrode plate arearranged on the end surface of the motor. The first electrode plate andthe second electrode plate are formed in a substantial horseshoe shape,and surround a rotating shaft of the motor. The multi-phase switchingelement group controls an electric current supplied to the stator of themotor. The number of the multi-phase switching element groupscorresponds to the number of phases of the motor. Each multi-phaseswitching element group includes a plurality of arms. Each arm includesa first switching device and a second switching device which areelectrically connected to each other in series between the firstelectrode plate and the second electrode plate. A plurality of the firstswitching devices is directly attached to the first electrode plate, anda plurality of the second switching devices is directly attached to thesecond electrode plate. Each of the plurality of the first switchingdevices and the second switching devices includes a first electrode, asecond electrode, a switching element electrically connected to thefirst electrode and the second electrode and sandwiched between thefirst electrode and the second electrode, and a sealing member which isprovided around the switching element and which contacts the firstelectrode and the second electrode.

Accordingly, with the switching device, the size thereof can be reduced,and the switching element can be efficiently cooled. As a result, themountability of the generator-motor apparatus can be improved.

Preferably, the generator-motor apparatus further includes a controlcircuit and a bus bar. The control circuit controls the multi-phaseswitching element group. The bus bar connects the plurality of the firstswitching devices and the plurality of the second switching devices tothe control circuit. The bus bar is formed by insert molding.

In this case, reliability and productivity of the generator-motor can beimproved.

Preferably, the generator-motor apparatus further includes a temperaturesensor. The temperature sensor is provided inside the control circuit,and detects the temperature of the control circuit. The temperature ofthe control circuit actually detected by the temperature sensor is usedfor detecting the temperature of the switching element.

In this case, the number of the wire harnesses can be reduced, and themountability of the generator-motor apparatus can be improved ascompared to the case where a temperature sensor is provided in each ofthe plurality of the switching elements.

The temperature of the switching element is preferably detected byextracting the temperature of the switching element corresponding to thetemperature of the control circuit actually detected by the temperaturesensor, with reference to a map showing a relationship between thetemperature of the control circuit and the temperature of the switchingelement.

In this case, the temperature of the switching element can be stablydetected.

Preferably, the multi-phase switching element group controls a currentsupplied to the stator such that the motor outputs predetermined torquewhen an internal combustion engine is ignited. The motor outputs thepredetermined torque, and transmits the predetermined torque to theinternal combustion engine via a belt.

In this case, flexibility in the mounting of the generator-motorapparatus can be increased.

Preferably, the generator-motor apparatus further includes a controlcircuit and a temperature sensor. The control circuit controls themulti-phase switching element group. The temperature sensor is arrangedon one of the first electrode plate and the second electrode plate, anddetects the ambient temperature of the electrode plate on which thetemperature sensor is arranged. The control circuit then detects thetemperature of the switching element based on the ambient temperatureactually detected by the temperature sensor.

In this case, the number of the wire harnesses can be reduced, and themountability of the generator-motor apparatus can be improved ascompared to the case where a temperature sensor is provided in each ofthe plurality of the switching elements.

Preferably, the control circuit stores a map showing a relationshipbetween the ambient temperature and the temperature of the switchingelement, and detects the temperature of the switching element byextracting the temperature of the switching element corresponding to theambient temperature actually detected by the temperature sensor usingthe map.

In this case, the temperature of the switching element can be stablydetected.

A third aspect of the invention relates to a drive system including agenerator-motor apparatus and a control device. The generator-motorapparatus starts an internal combustion engine, and generates electricpower using engine torque. The control device controls thegenerator-motor apparatus. The generator-motor apparatus includes amotor, a first electrode plate, a second electrode plate, and amulti-phase switching element group. The motor includes a rotor and astator, and serves as an electric power generator and an electric motor.The first electrode plate and the second electrode plate are arranged onthe end surface of the motor. The first electrode plate and the secondelectrode plate are formed in a substantial horseshoe shape, andsurround a rotating shaft of the motor. The multi-phase switchingelement group controls an electric current supplied to the stator of themotor. The number of the multi-phase switching element groupscorresponds to the number of phases of the motor. Each multi-phaseswitching element group includes a plurality of arms. Each arm includesa first switching device and a second switching device which areelectrically connected to each other in series between the firstelectrode plate and the second electrode plate. A plurality of the firstswitching devices is directly attached to the first electrode plate, anda plurality of the second switching devices is directly attached to thesecond electrode plate. Each of the plurality of the first switchingdevices and the second switching devices includes a first electrode, asecond electrode, a switching element electrically connected to thefirst electrode and the second electrode and sandwiched between thefirst electrode and the second electrode, and a sealing member which isprovided around the switching element and which contacts the firstelectrode and the second electrode. The control device outputs a signalfor prohibiting an automatic stop of the internal combustion engine toan internal combustion engine control device for controlling theinternal combustion engine, when the temperature of the switchingelement is higher than a predetermined temperature.

Accordingly, with the drive system, the mountability of thegenerator-motor apparatus can be improved, and the possibility, that theinternal combustion engine cannot be started due to an increase in thetemperature of the switching element included in the generator-motorapparatus, can be prevented.

A fourth aspect of the invention relates to a drive system including agenerator-motor apparatus and a control device. The generator-motorapparatus starts an internal combustion engine, and generates electricpower using engine torque. The control device controls thegenerator-motor apparatus. The generator-motor apparatus includes amotor, a first electrode plate, a second electrode plate, and amulti-phase switching element group. The motor includes a rotor and astator, and serves as an electric power generator and an electric motor.The first electrode plate and the second electrode plate are arranged onthe end surface of the motor. The first electrode plate and the secondelectrode plate are formed in a substantial horseshoe shape, andsurround a rotating shaft of the motor. The multi-phase switchingelement group controls an electric current supplied to the stator of themotor. The number of the multi-phase switching element groupscorresponds to the number of phases of the motor. Each multi-phaseswitching element group includes a plurality of arms. Each arm includesa first switching device and a second switching device which areelectrically connected to each other in series between the firstelectrode plate and the second electrode plate. A plurality of the firstswitching devices is directly attached to the first electrode plate, anda plurality of the second switching devices is directly attached to thesecond electrode plate. Each of the first and second switching devicesincludes a first electrode, a second electrode, a switching elementelectrically connected to the first electrode and the second electrodeand sandwiched between the first electrode and the second electrode, anda sealing member which is provided around the switching element andwhich contacts the first electrode and the second electrode. The controldevice controls the amount of electric power generated by the motor suchthat the temperature of the switching element becomes the temperature atwhich starting of the internal combustion engine is permitted.

Accordingly, with the drive system, the mountability of thegenerator-motor apparatus can be improved, and the possibility that theinternal combustion engine cannot be started due to an increase in thetemperature of the switching element included in the generator-motorapparatus can be prevented.

A fifth aspect of the invention relates to a computer-readable recordingmedium on which a program for directing a computer to perform control ofa generator-motor apparatus for starting an internal combustion engineis recorded. The generator-motor apparatus includes a motor, a firstelectrode plate, a second electrode plate, and a multi-phase switchingelement group. The motor includes a rotor and a stator, and serves as anelectric power generator and an electric motor. The first electrodeplate and the second electrode plate are arranged on the end surface ofthe motor. The first electrode plate and the second electrode plate areformed in a substantial horseshoe shape, and surround a rotating shaftof the motor. The multi-phase switching element group controls anelectric current supplied to the stator of the motor. The number of themulti-phase switching element groups corresponds to the number of phasesof the motor. Each multi-phase switching element group includes aplurality of arms. Each arm includes a first switching device and asecond switching device which are electrically connected to each otherin series between the first electrode plate and the second electrodeplate. A plurality of the first switching devices is directly attachedto the first electrode plate, and a plurality of the second switchingdevices is directly attached to the second electrode plate. Each of theplurality of the first switching devices and the second switchingdevices includes a first electrode, a second electrode, a switchingelement electrically connected to the first electrode and the secondelectrode and sandwiched between the first electrode and the secondelectrode, and a sealing member which is provided around the switchingelement and which contacts the first electrode and the second electrode.

The program directs the computer to perform a first step for detectingthe temperature of the switching element when the motor generateselectric power, a second step for determining whether the detectedtemperature of the switching element is higher than a first referencevalue, and a third step for prohibiting an automatic stop of theinternal combustion engine when the temperature of the switching elementis higher than the first reference value.

Accordingly, with the recording medium the possibility of the internalcombustion engine not being able to be started due to an increase in thetemperature of the switching element included in the generator-motorapparatus can be prevented.

Preferably, the program directs the computer to further perform a fourthstep for detecting the remaining capacity of a battery, a fifth step fordetermining whether the temperature of the switching element is higherthan a second reference value when the temperature of the switchingelement is equal to or lower than the first reference value, a sixthstep for determining whether the remaining capacity of the battery islarger than a reference capacity when the temperature of the switchingelement is higher than the second reference value, and a seventh stepfor limiting the amount of electric power generated by the motor suchthat the temperature of the switching element becomes equal to or lowerthan the second reference value when the remaining capacity of thebattery is larger than the reference capacity.

In this case, it is possible to prevent the possibility that theinternal combustion engine cannot be started due to an increase in thetemperature of the switching element included in the generator-motorapparatus.

Preferably, the program directs the computer to further perform aneighth step for lighting an alarm light when the remaining capacity ofthe battery does not increase even if a predetermined time has elapsedsince the motor starts electric power generation.

In this case, it is possible to prevent the possibility that theinternal combustion engine cannot be started due to an increase in thetemperature of the switching element included in the generator-motorapparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and further objects, features and advantages of theinvention will become apparent from the following description ofpreferred embodiments with reference to the accompanying drawings,wherein like numerals are used to represent like elements and wherein:

FIG. 1 is a plan view of a generator-motor apparatus according to anembodiment of the invention;

FIG. 2 is a cross sectional view taken along line II-II in FIG. 1;

FIG. 3 is a cross sectional view of a region where a switching deviceSW1, and a switching device SW2 shown in FIG. 1 are arranged;

FIG. 4 is a cross sectional view of the switching device SW1 shown inFIG. 1;

FIG. 5 is a plan view of a position detecting device shown in FIG. 2;

FIG. 6 is a cross sectional view for describing a method of connecting acontrol circuit shown in FIG. 2 to the switching devices;

FIG. 7 is a procedural flow chart for fixing the switching devices andelectrode plates to an end surface of an alternator;

FIG. 8 is a view showing connection among the position detecting device,a control IC, and an exciting transistor;

FIG. 9 is a circuit diagram showing switching devices SW1 to SW6 andelectrode plates shown in FIG. 1;

FIG. 10 is a block diagram showing an engine system including thegenerator-motor apparatus shown in FIG. 1;

FIG. 11 is a system diagram for describing detection of an abnormalityin electric power generation by the alternator, control of the amount ofelectric power generated by the alternator, and detection of anabnormality in battery charging;

FIGS. 12A and 12B are a flowchart for describing a routine for detectingan abnormality in electric power generation by the alternator andcontrolling the amount of electric power generated by the alternator;

FIG. 13 is a flowchart for describing a routine for detecting anabnormality in battery charging; and

FIG. 14 is a graph showing a relationship between the amount of electricpower generation and the state-of-charge of the battery.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereafter, an embodiment of the invention will be described in detailwith reference to accompanying drawings. The same portions orsubstantially the same portions in the drawings will be denoted with thesame reference numerals and characters, and description thereof will begiven only once.

Referring to FIG. 1, a generator-motor apparatus 100 according to theembodiment includes switching devices SW1 to SW6, a control circuit 20,an alternator 50, a bus bar 70 and electrode plates 83 and 84.

The electrode plates 83 and 84 have a substantial horseshoe shape, andare provided on an end surface of the alternator 50 so as to surround arotating shaft 50A of the alternator 50. The electrode plates 83 and 84are made of copper (Cu). The electrode plate 83 is connected to aterminal 90 to which a power supply voltage is supplied from a battery(not shown). The electrode plate 84 is connected to an earth node.

The control circuit 20 is provided on the end surface of the alternator50 and a notch portion of the electrode plates 83 and 84.

The switching devices SW1, SW3 and SW5 are directly attached to theelectrode plate 83 by means of soldering. The switching devices SW2, SW4and SW6 are directly attached to the electrode plate 84 by means ofsoldering.

The bus bar 70 includes wires 71 to 79 and connection portions 80 to 82.The wire 71 has one end connected to the control circuit 20 and theother end connected to a gate of the switching device SW1. The wire 72has one end connected to the control circuit 20 and the other endconnected to a gate of the switching device SW2. The wire 73 connectsthe connection portion 80 to the control circuit 20.

The wire 74 has one end connected to the control circuit 20 and theother end connected to a gate of the switching device SW3. The wire 75has one end connected to the control circuit 20 and the other endconnected to a gate of the switching device SW4. The wire 76 connectsthe connection portion 81 to the control circuit 20.

The wire 77 has one end connected to the control circuit 20 and theother end connected to a gate of the switching device SW5. The wire 78has one end connected to the control circuit 20 and the other endconnected to a gate of the switching device SW6. The wire 79 connectsthe connection portion 82 to the control circuit 20.

The connection portion 80 connects a source of the switching device SW1,a drain of the switching device SW2, and a terminal 51A to each other.The connection portion 81 connects a source of the switching device SW3,a drain of the switching device SW4, and a terminal 52A to each other.The connection portion 82 connects a source of the switching device SW5,a drain of the switching device SW6, and a terminal 53A to each other.The terminal 51A, the terminal 52A, and the terminal 53A are used forexchanging electric power with a U-phase coil, a V-phase coil, and aW-phase coil of the alternator 50, respectively.

The switching device SW1 and the switching device SW2 are electricallyconnected to each other in series between the electrode plate 83 and theelectrode plate 84 by the connection portion 80. The switching deviceSW3 and the switching device SW4 are electrically connected to eachother in series between the electrode plate 83 and the electrode plate84 by the connection portion 81. The switching device SW5 and theswitching device SW6 are electrically connected to each other in seriesbetween the electrode plate 83 and the electrode plate 84 by theconnection portion 82.

The connection portion 80 receives a waveform of electricity, which isgenerated by the U-phase coil when the alternator 50 serves as anelectric power generator, from the U-phase coil via the terminal 51A,and outputs the received wave form to the control circuit 20 via thewire 73. Similarly, the connection portion 81 receives a wave form ofelectricity generated by the V-phase coil from the V-phase coil via theterminal 52A, and outputs the received wave form to the control circuit20 via the wire 76.

The control circuit 20, as described later in detail, controls theswitching devices SW1 to SW6, the alternator 50, and the like.

FIG. 2 is a cross sectional view of the alternator 50, taken along lineII-II in FIG. 1.

Referring to FIG. 2, a rotor 55 is fixed to the rotating shaft 50A, anda rotor coil 54 is winded around the rotor 55. Stators 56 and 57 arefixed to the outside of the rotor 55, a U-phase coil 51 is winded aroundthe stator 56, and a V-phase coil 52 is winded around the stator 57. InFIG. 2, the stator around which a W-phase coil is winded is not shown.

A pulley 160 is coupled to one end of the rotating shaft 50A. Thisstructure allows the torque generated by the alternator 50 to betransmitted to a crankshaft of an engine via a belt, and the enginetorque from the crankshaft of the engine to be transmitted to therotating shaft 50A.

At one end of the rotating shaft 50A, which is on the opposite side ofthe end to which the pulley 160 is coupled, the electrode plates 83 and84 are provided so as to surround the rotating shaft 50A. A brush 58 isprovided so as to contact the rotating shaft 50A.

A position detecting device 40 is provided in the region which is on theright side with respect to the electrode plate 84 and on the upper sidewith respect to the rotating shaft 50A in FIG. 2. The control circuit 20is provided on the upper side of the position detecting device 40. Theswitching device SW3 is fixed to the surface of the electrode plate 83facing the electrode plate 84.

FIG. 3 is a cross sectional view of the region where the switchingdevices SW1 and SW2 shown in FIG. 1 are provided. Referring to FIG. 3,the switching device SW1 and the switching device SW2 are electricallyconnected to each other in series between the electrode plate 83 and theelectrode plate 84. The drain of the switching device SW1 is attached tothe electrode plate 83 by means of soldering, allowing the switchingdevice SW1 to be directly attached to the electrode plate 83. The sourceof the switching device SW2 is attached to the electrode plate 84 bymeans of soldering, allowing the switching device SW2 to be directlyattached to the electrode plate 84. The source of the switching deviceSW1 is connected to the drain of the switching device SW2 by theconnection portion 80.

In the same manner in which the switching device SW1 and the switchingdevice SW2 are connected to each other, the switching device SW3 and theswitching device SW4 are electrically connected to each other in seriesbetween the electrode plate 83 and the electrode plate 84, and theswitching device SW5 and the switching device SW6 are electricallyconnected to each other in series between the electrode plate 83 and theelectrode plate 84.

FIG. 4 is a cross sectional view of the switching device SW1 shown inFIG. 1. Referring to FIG. 4, the switching device SW1 includes a MOStransistor Tr1, electrodes 1 and 2, a resin 5, an insulation pad 6, anda wire 7. The MOS transistor Tr1 is an N channel MOS transistor.

The electrodes 1 and 2 are made of copper (Cu). The electrode 1 formsthe positive electrode, and the electrode 2 forms the negativeelectrode. The electrode 1 has a shape symmetrical to that of theelectrode 2. The electrode 1 and the electrode 2 sandwich the MOStransistor Tr1. In this case, a drain D of the MOS transistor Tr1 iselectrically connected to the electrode 1 by solder 3, and a source S iselectrically connected to the electrode 2 by solder 4. A gate G iselectrically connected to the wire 7 by means of soldering. The wire 7is insulated from the electrode 2 by the insulation pad 6.

The resin 5 is formed of a silicon (Si) resin. The resin 5 is providedin peripheral portions of the electrode 1 and the electrode 2sandwiching the MOS transistor Tr1, so as to contact the electrodes 1and 2, thereby sealing the MOS transistor Tr1. In this case, the wire 7connected to the gate of the MOS transistor Tr1 extends to the outsideof the region sealed by the electrodes 1 and 2, and the resin 5.

The electrode 1 is made of metal (Cu). The electrode 1 is connected tothe drain D of the MOS transistor Tr1 by the solder 3. This structureallows the electrode 1 to serve as a drain electrode of the switchingdevice SW and a cooling fin. The electrode 2 is made of metal (Cu). Theelectrode 2 is connected to the source S of the MOS transistor Tr1 bythe solder 4. This structure allows the electrode 2 to serve as a sourceelectrode of the switching device SW1 and a cooling fin.

Accordingly, heat generated by the MOS transistor Tr1 is transferred tothe electrode 1 via the drain D and the solder 3, transferred to theelectrode 2 via the source S and the solder 4, and then dissipated fromthe electrodes 1 and 2.

As described above, the switching device SW1 is sandwiched between thetwo electrodes 1 and 2, and is configured such that the heat generatedby the MOS transistor Tr1 is dissipated easily.

The resin 5 insulates the electrode 1 and the electrode 2 from eachother, and protects the MOS transistor from getting wet.

Each of the switching devices SW2 to SW6 has the same structure as thatof the switching device SW1. Note that the structure shown in FIG. 4 isreferred to as the “can structure”. By manufacturing the switchingdevices SW1 to SW6 using the “can structure”, the switching devicehaving reverse polarity can be manufactured only by vertically reversingthe arrangement of the switching devices SW1 to SW6, instead of bychanging the MOS transistors Tr1 to Tr6 from the N channel MOStransistors to the P channel MOS transistors. Namely, the “canstructure” allows the polarity to be reversed easily.

The switching devices SW1 to SW6 are configured such that the embeddedMOS transistors are easily cooled. The switching devices SW1, SW3 andSW5 are fixed to the electrode plate 83 by the drain D, and theswitching devices SW2, SW4 and SW6 are fixed to the electrode plate 84by the source S. The electrode plates 83 and 84 are arranged at the rearportion of the alternator 50, that is, the portion which is on theopposite side of the portion at which the pulley 160 is arranged.

Therefore, the electrode plates 83 and 84 are cooled by the air flowtaken in the alternator 50. In this case, since each of the switchingdevices SW1 to SW6 is configured by sandwiching the MOS transistorbetween the two electrodes (metal), the electrode 1 or the electrode 2which is not connected to the electrode plate 83 or the electrode plate84 is cooled together with the electrode plates 83 and 84.

Namely, in the switching devices SW1, SW3 and SW5, the heat generated bythe MOS transistor Tr1 is transferred to the electrode 1 or theelectrode 2 via the drain D or the source S, and then transferred to theelectrode plate 83 from the electrode 1. The heat transferred to theelectrode 2 and the electrode plate 83 is then cooled by the air flowtaken in the alternator 50. In the switching devices SW2, SW4 and SW6,the heat generated by the MOS transistor Tr1 is transferred to theelectrode 1 or the electrode 2 via the drain D or the source S, and thentransferred to the electrode plate 84 from the electrode 2. The heattransferred to the electrode 1 and the electrode plate 84 is cooled bythe air flow taken in the alternator 50.

When the switching devices SW1 to SW6 are fixed to the end surface ofthe alternator 50, each of the switching devices SW1 to SW6 is cooled byone of the electrode plates 83 and 84, and one of the electrodes 1 and2.

This eliminates the need for an additional device or the like forcooling switching devices SW1 to SW6. As a result, the switching devicesSW1 to SW6 can be efficiently cooled with a compact structure, and themountability can be improved when the generator-motor apparatus 100 ismounted in the vehicle.

FIG. 5 is a plan view of the position detecting device 40 shown in FIG.2. Referring to FIG. 5, the position detecting device 40 includes asubstrate 41, hall elements 42A, 42B and 42C, a circuit portion 43, andterminals 44 to 49.

The substrate 41 is made of silicon (Si). The hall elements 42A, 42B and42C are arranged on the substrate 41 on a certain periphery at regularintervals. The circuit portion 43 is also provided on the substrate 41.

The hall elements 42A, 42B and 42C detect a position detection signalshowing the position of a magnetic pole of the rotor 55 of thealternator 50, and outputs the detected position detection signal to thecircuit portion 43. This position detection signal has a sine waveform.

The terminal 44 receives a power supply voltage. The terminal 49 isconnected to the earth node. The terminal 48 receives a reference valueused for converting the position detection signals from the hallelements 42A, 42B and 42C from sine waveforms into rectangle waveforms.The terminals 45 to 47 output the position detection signals having arectangle waveform obtained by the circuit portion 43 to the controlcircuit 20.

The circuit portion 43 receives position detection signals θu, θv, andθw showing the magnetic pole positions of the U-phase, the V-phase andthe W-phase from the hall elements 41A, 42B, and 42C, respectively, andreceives the reference value from the terminal 48. The circuit portion43 then performs waveform shaping of the received position detectionsignals θu, θv, and θw, amplifies them, and converts them into theposition detection signals Hu, Hv, and Hw having a rectangle waveform,using the reference value received through the terminal 48. The circuitportion 43 then outputs the position detection signals Hu, Hv, and Hw tothe control circuit 20 via the terminals 45, 46 and 47, respectively.

In the embodiment, the position detecting device 40 is manufactured asone IC having the substrate 41, the hall elements 42A, 42B and 42C, andthe circuit portion 43 in one package, and having terminals 44 to 49.

Accordingly, the size of the generator-motor apparatus 100 can bereduced as compared to the case where the three hall elements arearranged at intervals of 30 electrical degrees on a printed substrate,enabling improvement in the mountability of the generator-motorapparatus 100.

FIG. 6 is a cross sectional view for describing a method of connecting acontrol circuit 20 shown in FIG. 2 to switching devices SW1 and SW2.Referring to FIG. 6, the control circuit 20 includes a control IC 21, anexciting transistor 22, and a substrate 23. The control IC 21 and theexciting transistor 22 are arranged on the substrate 22.

The bus bar 70 is formed by insert molding. Namely, the bus bar 70 ismanufactured by placing the wires 71 to 79 shown in FIG. 1 in a die andperforming molding using a resin. The bus bar 70 is then arrangedbetween the electrode plate 83 and the electrode plate 84. One end ofthe bus bar 70 is connected to the substrate 23 of the control circuit20 by TIG welding, and the other end is connected to the switchingdevices SW1, SW2, and the like.

A temperature sensor 60 is arranged on the electrode plate 84. Acondenser 30 is arranged near the control circuit 20.

The condenser 30 is connected to the input side of the switching devicesSW1 to SW6, and removes a ripple current. The temperature sensor 60detects the ambient temperature of the electrode plate 84, and outputsthe detected temperature to the control IC 21 of the control circuit 20.

The control IC 21 outputs a control signal through the bus bar 70 so asto control the switching devices SW1, SW2, and the like. The control IC21 also receives the waveform of electricity generated by the alternator50 through the bus bar 70, and determines whether the alternator 50actually generates electric power.

The control IC 21 controls the exciting transistor 22 so as to controlan electric current supplied to the rotor coil 54 of the alternator 50.Namely, the control IC 21 controls the amount of electric powergenerated by the alternator 50.

Further, the control IC 21 estimates the element temperature of the MOStransistor included in each of the switching devices SW1 to SW6 based onthe temperature detected by the temperature sensor 60. The control IC 21stores a map showing a relationship between the ambient temperature ofthe temperature sensor 60 and the element temperature. The control IC 21extracts the element temperature corresponding to the ambienttemperature actually detected by the temperature sensor 60 from the map,and estimates the element temperature.

As described above, the ambient temperature of the electrode plate 84 ismeasured and the element temperature is estimated, instead of directlymeasuring the element temperature of each of the switching devices SW1to SW6. This reduces the number of the wire harnesses connected to thecontrol circuit 20, enabling improvement in the mountability of thegenerator-motor apparatus 100.

The control IC 21 also has other functions, which will be describedlater. The temperature sensor 60 may be arranged on the electrode plate83. Namely, it is sufficient that the temperature sensor 60 be arrangedon only one of the two electrode plates 83 and 84.

FIG. 7 is a procedural flow chart for fixing the switching devices SW1to SW6 and the electrode plates 83 and 84 to the end surface of analternator 50. Referring to FIG. 7, the switching devices SW1 to SW6having the above-mentioned “can structure”, and the electrode plates 83and 84 having a substantial horseshoe shape are prepared. Then, theswitching devices SW1 and SW3 are fixed to one surface of the electrodeplate 83 by means of soldering (refer to step 7A in FIG. 7). In thiscase, the switching device SW5 is also fixed to the electrode plate 83by means of soldering (this step is not shown in step 7A in FIG. 7). Theswitching devices SW2, SW4, and SW6 are fixed to one surface of theelectrode plate 84 by means of soldering.

The electrode plate 83 with the switching devices SW1, SW3 and SW5soldered to one surface thereof is then placed in an oven with a weight.The switching devices SW1, SW3 and SW5, and the electrode plate 83 arethen heated (refer to step 7B in FIG. 7). This step increases adhesionbetween the switching devices SW1, SW3, and SW5, and the electrode plate83. In this case, the electrode plate 84 with the switching devices SW2,SW4 and SW6 soldered to one surface thereof is also placed in the ovenwith a weight. The switching devices SW2, SW4 and SW6, and the electrodeplate 84 are then heated.

Then, the electrode plates 83 and 84 are supported such that theswitching devices SW1, SW3, and SW5 face the switching devices SW2, SW4and SW6, respectively. The bus bar 70 formed by insert molding isarranged between the electrode plate 83 and the electrode plate 84. Thewires 71, 72, 74, 75, 77 and 78 included in the bus bar 70 are connectedto the gates of the switching devices SW1 to SW6, respectively. Theconnection portion 80 is connected to the source of the switching deviceSW1, the drain of the switching device SW2, and the terminal 51A. Theconnection portion 81 is connected to the source of the switching deviceSW3, the drain of the switching device SW4, and the terminal 52A. Theconnection portion 82 is connected to the source of the switching deviceSW5, the drain of the switching device SW6, and the terminal 53A (referto step 7C in FIG. 7).

Then, the switching devices SW1, SW3, and SW5, the electrode plate 83,the switching devices SW2, SW4, and SW6, and the electrode plate 84connected with each other by the bus bar 70 are fixed to the end surfaceof the alternator 50 (refer to step 7D in FIG. 7). The control circuit20 is then arranged in the notch portion of the electrode plates 83 and84. One end of the bus bar 70 is connected to the substrate 23 of thecontrol circuit 20 by TIG welding.

A series of steps is thus completed. FIG. 8 is a diagram showingconnection among the position detecting device 40, the control IC 21,and an exciting transistor 22. Referring to FIG. 8, the control IC 21includes a control portion 211, a MOS drive portion 212, and atemperature sensor 213. When a start key IG of the vehicle in which thegenerator-motor apparatus 100 is mounted is turned ON, the control IC 21receives a power supply current at a positive terminal voltage +B of thepower supply via the terminal 21A. The power supply current is alsosupplied to the terminal 44 of the position detecting device 40 and aterminal 22A of the exciting transistor 22.

When the alternator 50 is not generating electric power, the controlportion 211 notifies a host ECU (Electrical Control Unit) of anabnormality in the alternator 50 via a terminal 21B. When the SOC of thebattery is small, the control portion 211 lights a charge lamp based ona charge lamp signal CHG received via the terminal 21B.

The control portion 211 receives a signal M/G via a terminal 21C, andcontrols the switching devices SW1 to SW6 based on the received signalM/G, so as to operate the alternator 50 as an electric motor or anelectric power generator.

Further, the control portion 211 receives an adjustment command voltageReg. V via a terminal 21D, and controls the switching devices SW1 to SW6so as to output the received adjustment command voltage Reg. V to thealternator 50.

Further, the control portion 211 receives a waveform of electricitygenerated by each phase of the alternator 50 via terminals 21L, 21M, and21N, and determines whether the alternator 50 generates electric powernormally, based on the received wave form. The terminals 21L, 21M and21N are connected to terminals 21I, 21J, and 21K, respectively, via acondenser.

Further, the control portion 211 outputs a control signal forcontrolling the gate of the exciting transistor 22 to a terminal 22B ofthe exciting transistor 22 via a terminal 21V. Namely, the controlportion 211 controls the amount of electric power generated by thealternator 50 via the terminal 21V.

The MOS drive portion 212 outputs the reference value, which is used forconverting the position detection signals θu, θv, and θw detected by thehall elements 42A, 42B and 42C into the position detection signals Hu,Hv, and Hw having a rectangle waveform, to the terminal 48 of theposition detecting device 40 via a terminal 21H.

The MOS drive portion 212 receives the detection signals Hu, Hv and Hwfrom the position detecting device 40 via terminals 21E, 21F and 21G,and generates drive signals for driving the switching devices SW1 to SW6in synchronization with the rising timing and the falling timing of eachof the received position detection signals Hu, Hv and Hw. The MOS driveportion 212 outputs the generated drive signals to the switching devicesSW1 to SW6 via terminals 21O, 21P, 21Q, 21R, 21S and 21T, respectively.

The temperature sensor 213 detects the temperature of the control IC 21,and outputs the detected temperature to an after-mentioned eco-run ECU230.

A terminal 21U is connected to a ground GND. The exciting transistor 22receives a power supply current via the terminal 22A. The excitingtransistor 22 supplies a direct current corresponding to the controlsignal received by the gate via the terminal 22B to the rotor coil 54 ofthe alternator 50 from the terminal 21C.

FIG. 9 is a circuit diagram showing switching devices SW1 to SW6 andelectrode plates 83 and 84 shown in FIG. 1. FIG. 9 shows the MOStransistors Tr1 to Tr6 included in the switching devices SW1 to SW6,respectively.

The MOS transistors Tr1 and Tr2 are connected to each other in seriesbetween a power supply line LN1 constituted of the electrode plate 83and an earth line LN2 constituted of the electrode plate 84. Similarly,the MOS transistors Tr3 and Tr4 are connected to each other in seriesbetween the power supply line LN1 and the earth line LN2, and the MOStransistors Tr5 and Tr6 are connected to each other in series betweenthe power supply line LN1 and the earth line LN2.

The pair of the MOS transistors Tr1 and Tr2, the pair of the MOStransistors Tr3 and Tr4, and the pair of the MOS transistors Tr5 and Tr6are connected in parallel, between the power supply line LN1 and theearth line LN2.

The U-phase coil of the alternator 50 is connected to a point locatedmidway between the MOS transistor Tr1 and the MOS transistor Tr2. TheV-phase coil of the alternator 50 is connected to a point located midwaybetween the MOS transistor Tr3 and the MOS transistor Tr4. The W-phasecoil of the alternator 50 is connected to a point located midway betweenthe MOS transistor Tr5 and the MOS transistor Tr6.

The condenser 30 is connected to the input side of the MOS transistorsTr1 to Tr6. The condenser 30 removes a ripple current.

The MOS transistors Tr1 to Tr6 constitute an inverter INV. In theinverter INV, the MOS transistors Tr1 to Tr6 are turned ON/OFF accordingto the drive signals from the terminals 21O, 21P, 21Q, 21R, 21S and 21Tof the control IC 21, whereby the alternator 50 is driven as an electricmotor.

When the alternator 50 serves as an electric power generator, theinverter INV converts an alternating voltage generated by the alternator50 into a direct-current voltage, and supplies the direct-currentvoltage to the battery. In the case where loss of electric power duringconversion from an alternating voltage to a direct-current voltage isreduced, the inverter INV turns the MOS transistors Tr1 to Tr6 ON/OFF,thereby converting an alternating voltage to a direct-current voltage.In the other cases, an alternating voltage is converted into adirect-current voltage by virtual diodes of the MOS transistors Tr1 toTr6.

The MOS transistors Tr1 and Tr2 connected to each other in seriesconstitute one arm, the MOS transistors Tr3 and Tr4 connected to eachother in series constitute one arm, and the MOS Tr5 and Tr6 connected toeach other in series constitute one arm. Namely the inverter INV isconstituted of three arms.

In the embodiment, the number of the arms is not limited to three.Generally, the number of the arms is decided according to the number ofthe phases of the alternator 50. Therefore, when the alternator 50includes a plurality of phases, the inverter INV includes a plurality ofarms.

FIG. 10 is a block diagram of an engine system 200 including thegenerator-motor apparatus shown in FIG. 1. Referring to FIG. 10, theengine system 200 includes the battery 100, the control circuit 20, thealternator 50, an engine 110, a torque converter 120, an automatictransmission 130, pulleys 140, 150, and 160, a belt 170, auxiliaries172, a starter 174, an electrohydraulic pump 180, a fuel injection valve190, an electric motor 210, a throttle valve 220, the eco-run ECU 230,an engine ECU 240, and a VSC (Vehicle Stability Control) ECU 250.

The control circuit 20 is provided on the end surface of the alternator50, as described above. The engine 110 is started by the alternator 50or the starter 174, and generates a predetermined amount of output. Moreparticularly, the engine 110 is started by the alternator 50 when beingstarted after the stop by the economy running system (hereinafter,referred to as the “eco-run system” where appropriate). The engine 110is started by the starter 174 when being started by the ignition key.The engine 110 transmits the generated output from a crankshaft 110 a tothe torque converter 120 or the pulley 140.

The torque converter 120 transmits rotation of the engine 110 from thecrankshaft 110 a to the automatic transmission 130. The automatictransmission 130 performs automatic shift control, and changes thetorque from the torque converter 120 to torque corresponding to theshift control, and then outputs the torque to an output shaft 130 a.

The pulley 140 is coupled to the crankshaft 110 a of the engine 110 viaan electromagnetic clutch 140 a. The pulley 140 operates in accordancewith the pulleys 150 and 160 via the belt 170.

The electromagnetic clutch 140 a connects/disconnects the pulley 140to/from the crankshaft 110 a according to the control by the eco-run ECU230. The belt 170 couples the pulleys 140, 150 and 160 to each other.The pulley 150 is coupled to the rotating shaft of the auxiliaries 172.

The pulley 160 is coupled to the rotating shaft of the alternator 50,and is rotated by the alternator 50 or the crankshaft 110 a of theengine 110.

The auxiliaries 172 are constituted of one of or some of anair-conditioner compressor, a power steering pump and an engine coolingwater pump. The auxiliaries 172 receive the output from the alternator50 via the pulley 160, the belt 170 and the pulley 150, and are drivenby the received output.

The alternator 50 is driven by the control circuit 20. The alternator 50receives the rotating force of the crankshaft 110 a of the engine 110via the pulley 140, the belt 170 and the pulley 160, and converts thereceived rotating force to electric energy. Namely, the alternator 50generates electric power using the rotating force of the crankshaft 110a. In two cases, the alternator 50 generates electric power. In one ofthe cases, by driving the engine 110 while a hybrid vehicle includingthe engine system 200 is running normally, the alternator 50 receivesthe rotating force of the crankshaft 110 a and generates electric power.In the other case, although the engine 110 is not driven, the rotatingforce of drive wheels is transmitted to the crankshaft 110 a while thehybrid vehicle is decelerating, and the alternator 50 receives thetransmitted rotating force and generates electric power.

The alternator 50 is driven by the control circuit 20, and transmits apredetermined amount of output (power) to the pulley 160. When theengine 110 is started, the predetermined amount of output is transmittedto the crankshaft 110 a of the engine 110 via the belt 170 and thepulley 140. When the auxiliaries 172 are driven, the predeterminedamount of output is transmitted to the auxiliaries 172 via the belt 170and the pulley 150.

The battery 10, for example, supplies a direct-current voltage of 12V tothe control circuit 20. The control circuit 20 converts thedirect-current voltage from the battery 10 to an alternating voltageaccording to control by the eco-run ECU 230, and drives the alternator50 using the obtained alternating voltage. The control circuit 20converts an alternating voltage generated by the alternator 50 to adirect-current voltage according to control by the eco-run ECU 230, andcharges the battery 10 using the obtained direct-current voltage.

The starter 174 starts the engine 110 according to control by theeco-run ECU 230. The electrohydraulic pump 180 is embedded in theautomatic transmission 130, and supplies hydraulic fluid to a hydraulicpressure control portion provided in the automatic transmission 130according to control by the engine ECU 240. The hydraulic fluid is usedfor adjusting the operation states of a clutch, a brake and a one-wayclutch in the automatic transmission 130 and changing the shift state asrequired, by a control valve in the hydraulic pressure control portion.

The eco-run ECU 230 performs mode control of the alternator 50 and thecontrol circuit 20, control of the starter 174, control of thestate-of-charge of the battery 10, detection of an abnormality inelectric power generation by the alternator 50, control of the amount ofelectric power generated by the alternator 50, and detection of anabnormality in charging of the battery 10. The mode control of thealternator 50 and the control circuit 20 includes control of an electricpower generation mode where the alternator 50 serves as an electricpower generator and control of a drive mode where the alternator 50serves as a drive motor. Note that the control line from the eco-run ECU230 to the battery 10 is not shown in the figure.

The fuel injection valve 190 controls fuel injection according tocontrol by the engine ECU 240. The electric motor 210 controls theopening amount of the throttle valve 220 according to control by theengine ECU 240. The opening amount of the throttle valve 220 is set to apredetermined value by the electric motor 210.

The engine ECU 240 performs ON/OFF control of the auxiliaries 172 otherthan the engine cooling water pump, drive control of theelectrohydraulic pump 180, shift control of the automatic transmission130, fuel injection control by the fuel injection valve 190, the openingamount control of throttle valve 220, performed by the electric motor210, and the other engine control.

The engine ECU 240 detects an engine coolant temperature THW from acoolant temperature sensor, a signal indicative of whether anaccelerator pedal is depressed from an idle switch, an accelerator pedaloperation amount ACCP from an accelerator pedal operation amount sensor,a rudder angle of steering from a rudder angle sensor, a vehicle speedSPD from a vehicle speed sensor, a throttle valve opening amount TA froma throttle valve opening amount sensor, a shift position SHFT from ashift position sensor, an engine rotational speed NE from an enginerotational speed sensor, a signal indicative of whether ON/OFF operationis performed from an air-conditioner switch, and the other data.

The VSC-ECU 250 detects a signal indicative of whether a brake pedal isdepressed from a brake switch and the other data.

Each of the eco-run ECU 230, the engine ECU 240 and the VSC-ECU 250mainly includes a microcomputer. The CPU (Central Processing Unit)performs required computation according to a program written in aninternal ROM (Read Only Memory), and the ECUs perform various types ofcontrol based on the result of the computation. The result of thecomputation, and the detected data can be transmitted among the eco-runECU 230, the engine ECU 240 and the VSC-ECU 250 via data communication.The eco-run ECU 230, the engine ECU 240 and the VSC-ECU 250 can exchangedata as required and perform control in accordance with each other.

As an operation of the engine system 200, known idle stop control isperformed. More particularly, the engine is stopped when deceleration orstop of the vehicle is detected based on the outputs from varioussensors. The engine 110 is then started by the alternator 50 when thedriver intends to start the vehicle (the driver's intention can bedetected based on the operation states of the brake and the acceleratorpedal). In the engine system 200, the control circuit 20 for controllingthe alternator 50 is provided on the end surface of the alternator 50,and drives the alternator 50 as a drive motor or an electric powergenerator according to an instruction from the eco-run ECU 230. When thealternator 50 is driven as a drive motor or an electric power generator,heat generated by the MOS transistors Tr1 to Tr6 of the switchingdevices SW1 to SW6 is transferred to the electrode plate 83 or theelectrode plate 84 via the electrode 1 or the electrode 2, whereby theMOS transistors Tr1 to Tr6 are efficiently cooled.

Hereafter, description will be made on detection of an abnormality inelectric power generation by the alternator 50, control of the amount ofelectric power generated by the alternator 50 and detection of anabnormality in charging of the battery 10 performed by the alternator 50in the engine system 200, which are performed by the eco-run ECU 230.

FIG. 11 is a system diagram for describing detection of an abnormalityin electric power generation by the alternator 50, control of the amountof electric power generated by the alternator 50 and detection of anabnormality in charging of the battery 10. Referring to FIG. 11, theeco-run ECU 230 receives values of the battery currents input in/outputfrom the battery 10 from a current sensor 11. The eco-run ECU 30accumulates the values of the battery currents, and computes the SOC(state-of-charge) of the battery 10.

A terminal TEMP receives a temperature of the control IC 21 from thetemperature sensor 213 (refer to FIG. 8) provided in the control IC 21,and the eco-run ECU 230 estimates element temperatures of the switchingdevices SW1 to SW6 based on the received temperature. The eco-run ECU230 stores a map showing a relationship between the temperature of thecontrol IC 21 and the element temperature, and extracts the temperaturecorresponding to the temperature of the control IC 21 received from thetemperature sensor 213 from the map so as to estimate the elementtemperatures.

The eco-run ECU 230 then performs detection of an abnormality inelectric power generation by the alternator 50 and control of the amountof electric power generated by the alternator 50 based on the estimatedelement temperatures. The eco-run ECU 230 then performs detection of anabnormality in charging of the battery 10 based on the estimated elementtemperatures and the computed SOC of the battery 10.

FIGS. 12A and 12B are a flowchart for describing the routine forperforming detection of an abnormality in electric power generation bythe alternator 50 and control of the amount of electric power generatedby the alternator 50. Referring to FIGS. 12A and 12B, when the routineis started, the eco-run ECU 230 sets “eco-run permission=1” afterconfirming that the eco-run condition is satisfied (step S1). Namely,the eco-run ECU 230 permits operation for stopping the engine 110, whenthe hybrid vehicle equipped with the engine system 200 stops due to astop light or the like.

The eco-run ECU 230 then receives the temperature of the control IC 21from the temperature sensor 213 in the control IC 21, and estimates theelement temperatures of the switching devices SW1 to SW6 correspondingto the received temperature of the control IC 21 in the above-mentionedmanner (step S2). The eco-run ECU 230 then receives the values of thebattery currents from the current sensor 11, and accumulates thereceived values of the battery currents so as to read the SOC of thebattery 10 (step S3).

The eco-run ECU 230 then determines whether a start command is beingperformed, that is, whether the alternator 50 is operated as an electricmotor and the engine 110 is being started (step S4). More particularly,the eco-run ECU 230 determines whether the engine 110 is being startedbased on whether a signal “M/G=1” is being output to the control IC 21.

When the eco-run ECU 20 determines that the engine 110 is being started,step S12 is then performed.

On the other hand, when the eco-run ECU 230 determines in step S4 thatthe engine 110 is not being started, the eco-run ECU 230 determinedwhether the element temperature estimated in step S2 is higher than areference value T0 (step S5). The reference value T0 is the criticaltemperature at which the alternator 50 can continue serving as anelectric power generator.

When the element temperature is determined to be higher than thereference value T0, the eco-run ECU 230 generates “exciting currentcommand=0” for setting the exciting current supplied from the excitingtransistor 22 to “0”, and outputs it to the control IC 21. The controlIC 21 then controls the exciting transistor 22 such that the excitingcurrent becomes “0”, whereby electric power generation by the alternator50 is stopped. The eco-run ECU 230 then lights a warning lamp fornotifying the driver that electric power cannot be generated (step S6),afterwhich, the routine ends.

When it is determined in step S5 that the element temperature is higherthan the reference value T0, the alternator 50 is controlled such thatpower generation is stopped due to the following reason: if powergeneration by the alternator 50 is continued when the elementtemperature is higher than the reference value T0, the switching devicesSW1 to SW6 are broken, which makes it impossible to operate thealternator 50 as an electric motor after a stop of economy running andto start the engine 110.

On the other hand, when it is determined in step S5 that the elementtemperature is equal to or lower than the reference value T0, theeco-run ECU 230 determines whether the element temperature is higherthan a reference value T1 (<T0) (step S7). The reference value T1 is thecritical temperature at which economy running is permitted.

When it is determined in step S7 that the element temperature is higherthan the reference value T1, the eco-run ECU 230 sets “eco-runpermission=0”, and outputs this “eco-run permission=0” to the engine ECU240 so as to prohibit economy running. Then eco-run ECU 230 then turnsoff an eco-run lamp, and notifies the driver that economy running isprohibited (step S8). The engine ECU 240 does not stop the engine 110even when the hybrid vehicle is stopped, according to “eco-runpermission=0” from the eco-run ECU 230. This eliminates the need forstarting the engine 110 using the alternator 50 when the hybrid vehicleis started after stop of economy running, preventing the elementtemperatures of the switching devices SW1 to SW6 from increasing. Then,step S12 is performed.

When the element temperature is higher than the reference value T1,economy running is prohibited in order to reduce the number of timesthat the engine 110 is started by the alternator 50 after stop ofeconomy running (namely, the number of times that the alternator 50 isdriven as an electric motor by the switching devices SW1 to SW6),thereby preventing the element temperatures of the switching devices SW1to SW6 from increasing.

On the other hand, when it is determined in step S7 that the elementtemperature is equal to or lower than the reference value T1, theeco-run ECU 230 determines whether the element temperature is higherthan a reference temperature T2 (step S9). The reference temperature T2is the critical temperature at which the amount of electric powergenerated by the alternator 50 is limited such that the elementtemperature does not exceed the reference value T1.

When it is determined that the element temperature is higher than thereference temperature T2, the eco-run ECU 230 further determines whetherthe SOC of the battery obtained in step S3 is larger than a referencevalue C (step S10). When the SOC of the battery is equal to or smallerthan the reference value C, step S12 is then performed.

On the other hand, when it is determined in step S10 that the SOC of thebattery is larger than the reference value C, the eco-run ECU 230controls the control IC 21 such that the amount of electric powergenerated by the alternator 50 is limited (step S11). More particularly,the eco-run 230 stores a map showing a relationship between the elementtemperature and the exciting current command. The eco-run ECU 230extracts the exciting current command corresponding to the elementtemperature obtained in step S2 using the map, and outputs the extractedexciting current command to the control IC 21. The control IC 21controls the exciting transistor 22 such that the exciting currentdesignated by the exciting current command from the eco-run ECU 230flows. The amount of electric power generated by the alternator 50 isthereby limited, and the element temperatures of the switching devicesSW1 to SW6 are limited to the temperature at which the alternator 50 canbe operated as an electric motor and the engine 110 can be started,afterwhich the routine ends.

On the other hand, when it is determined in step S9 that the elementtemperature is equal to or lower than the reference value T2, theeco-run ECU 230 sets “M/G=0” and permits the alternator 50 to generateelectric power normally (step S12), afterwhich the routine ends.

FIG. 13 is a flowchart for describing the routine for detecting anabnormality in charging of the battery 10. Referring to FIG. 13, whenthe routine is started, the eco-run ECU 230 resets a timer counter to“0” (TIME=0) (step S21). The eco-run ECU 230 then determines whether thealternator 50 is generating electric power (step S22). Moreparticularly, the eco-run ECU 230 determines whether the alternator 50is generating electric power by determining whether the signal M/G is“0”.

When it is determined in step S22 that the alternator 50 is notgenerating electric power, the routine ends.

On the other hand, when it is determined in step S22 that the alternator50 is generating electric power, the eco-run ECU 230 reads the value ofbattery current I from the current sensor 11 (step S23), and accumulatesthe values of the battery currents I so as to compute thestate-of-charge SOC of the battery 10 (step S24).

The eco-run ECU 230 controls the control IC 21 such that the amount ofelectric power corresponding to the computed state-of-charge SOC isgenerated by the alternator 50 (step S25). The eco-run ECU 230 stores amap showing a relationship between the electric power generation amountand the state-of-charge SOC shown in FIG. 14. The eco-run ECU 230extracts the electric power generation amount corresponding to thestate-of-charge SOC computed in step S24, and controls the control IC 21such that the extracted amount of electric power is generated by thealternator 50.

The eco-run ECU 230 determines whether the state-of-charge SOC hasreached the full charge (step S26). When it is determined that thestate-of-charge SOC has reached the full charge, the eco-run ECU 230turns off the warning lamp (step S28), afterwhich the routine ends.

On the other hand, when it is determined in step S26 that thestate-of-charge SOC has not reached the full charge, the eco-run ECU 230determines whether the battery current I is positive or negative (stepS27). In this case, the fact that the battery current I is positivesignifies that the battery current I is discharged from the battery 10,and the fact that the battery current I is negative signifies that thebattery current I is charged into the battery 10.

When it is determined in step S27 that the battery current I isnegative, the eco-run ECU 230 turns off the warning lamp (step S28),afterwhich the routine ends.

On the other hand, when it is determined in step S28 that the batterycurrent I is positive, the eco-run ECU 230 increases the value shown bythe timer counter (step S29), and determines whether the obtained timercount value TIME is larger than a reference value A (step S30). Thereference value A is the critical value of time at which it isdetermined that the battery 10 is not charged.

When it is determined in step S30 that the timer count value TIME islarger than the reference value A, the eco-run ECU 230 determines thatthe battery 10 is not charged, and lights the warning lamp (step S31),afterwhich the routine ends.

On the other hand, when it is determined in step S30 that the timercount value TIME is equal to or smaller than the reference value A,steps S22 to S30 are repeatedly performed.

Detection of an abnormality in power generation by the alternator 50 andcontrol of the amount of electric power generated by the alternator 50in the eco-run ECU 230 are actually performed by the CPU. The CPU readsthe program including the steps shown in the flowchart in FIGS. 12A and12B from the ROM, and performs the steps in FIGS. 12A and 12B so as toperform detection of an abnormality in power generation by thealternator 50 and control of the amount of electric power generated bythe alternator 50.

Accordingly, the ROM can be regarded as a computer (CPU)-readablerecording medium on which the program for directing the computer (CPU)to perform detection of an abnormality in electric power generation bythe alternator 50 and control of the amount of electric power generatedby the alternator 50 is recorded.

Detection of an abnormality in charging of the battery 10 in the eco-runECU 230 is actually performed by the CPU. The CPU reads the programincluding the steps shown in the flowchart in FIG. 13 from the ROM, andperforms the steps in FIG. 13 so as to detect an abnormality in chargingof the battery 10.

Accordingly, the ROM can be regarded as a computer (CPU)-readablerecording medium on which the program for directing the computer (CPU)to perform detection of an abnormality in charging of the battery 10 isrecorded.

As described above, the eco-run ECU 230 estimates the elementtemperatures of the switching devices SW1 to SW6 based on thetemperature detected by the temperature sensor 213 provided in thecontrol IC 21 of the generator-motor apparatus 100. The ECU 230 thenperforms detection of an abnormality in electric power generation by thealternator 50 and control of the amount of electric power generated bythe alternator 50 based on the estimated element temperatures.

The eco-run ECU 230 detects an abnormality in charging of the battery 10based on the value of the battery current from the current sensor 11provided near the battery 10.

Therefore, instead of a microcomputer performing detection of anabnormality in electric power generation by the alternator 50, controlof the amount of electric power generated by the alternator 50, anddetection of an abnormality in charging of the battery 10, theabove-mentioned one IC chip (the control IC 21) is provided on the endsurface of the alternator, enabling a reduction in size of thegenerator-motor apparatus 100. As a result, the mountability of thegenerator-motor apparatus 100 is improved.

In the above description, the positional relationship between thealternator 50 and the engine 110 is not described in detail. When theengine 110 is started by “ignition combined start”, the position wherethe alternator 50 is provided is not limited.

The “ignition combined start” signifies the state where fuel iscompressed in a cylinder of the engine 110 and ignited, the crankshaftstarts rotating, and the rotation is assisted by torque of the electricmotor so as to facilitate the start of the engine 110. In this case, theelectric motor outputs toque smaller than that in a normal state.

Accordingly, when the engine 110 is started by the “ignition combinedstart”, the output torque of the alternator 50 is transmitted to thecrankshaft 110 a of the engine 110 via the belt 170. Therefore, theposition where the alternator 50 is provided is not limited.

On the other hand, when the engine 110 is started without using the“ignition combined start”, the alternator 50 needs to output largetoque. Therefore, the alternator 50 is provided near the engine 110.

The alternator 50 can be regarded as a “motor” which includes a statorand a rotor and serves as an electric power generator and an electricmotor.

Each of the pairs of the switching devices SW1 and SW2, the switchingdevices SW3 and SW4, and the switching devices SW5 and SW6 can beregarded as a “multi-phase switching element group”.

The eco-run ECU 230 and the generator-motor apparatus 100 can beregarded as a “drive system”.

Further, the eco-run ECU 230 can be regarded as a “control device” whichcontrols the generator-motor apparatus 100.

While the invention has been described with reference to exemplaryembodiments thereof, is to be understood that the invention is notlimited to the exemplary embodiments or constructions. To the contrary,the invention is intended to cover various modifications and equivalentarrangements. In addition, while the various elements of the exemplaryembodiments are shown in various combinations and configurations, whichare exemplary, other combinations and configurations, including more,less or only a single element, are also within the spirit and scope ofthe invention.

1. A switching device, comprising: a first electrode; a secondelectrode; a switching element which is electrically connected to thefirst electrode and the second electrode, and sandwiched between thefirst electrode and the second electrode; and a sealing member which isprovided around the switching element, and which contacts the firstelectrode and the second electrode.
 2. The switching device according toclaim 1, wherein the switching element is electrically connected to thefirst electrode and the second electrode by means of soldering.
 3. Theswitching device according to claim 1, wherein the switching element isan N channel MOS transistor.
 4. A generator-motor apparatus, comprising:a motor which includes a rotor and a stator, and serves as an electricpower generator and an electric motor; a first electrode plate and asecond electrode plate which are arranged on an end surface of themotor, and formed in a substantial horseshoe shape so as to surround arotating shaft of the motor; and a multi-phase switching element groupwhich controls an electric current supplied to the stator, wherein thenumber of the multi-phase switching element groups corresponds to thenumber of phases of the motor; each multi-phase switching element groupincludes a plurality of arms each of which includes a first switchingdevice and a second switching device that are electrically connected toeach other in series between the first electrode plate and the secondelectrode plate; a plurality of the first switching devices is directlyattached to the first electrode plate; a plurality of the secondswitching devices is directly attached to the second electrode plate;and each of the plurality of the first switching devices and the secondswitching devices includes a first electrode, a second electrode, aswitching element electrically connected to the first electrode and thesecond electrode and sandwiched between the first electrode and thesecond electrode, and a sealing member which is provided around theswitching element and which contacts the first electrode and the secondelectrode.
 5. The generator-motor apparatus according to claim 4,further comprising: a control circuit which controls the multi-phaseswitching element group; and a bus bar which connects the plurality ofthe first switching devices and the plurality of the second switchingdevices to the control circuit, wherein the bus bar is formed by insertmolding.
 6. The generator-motor apparatus according to claim 4, furthercomprising: a temperature sensor which is provided inside the controlcircuit, and which detects a temperature of the control circuit, whereinthe temperature of the control circuit actually detected by thetemperature sensor is used for detecting a temperature of the switchingelement.
 7. The generator-motor apparatus according to claim 6, whereinthe temperature of the switching element is detected by extracting thetemperature of the switching element corresponding to the temperature ofthe control circuit actually detected by the temperature sensor, withreference to a map showing a relationship between the temperature of thecontrol circuit and the temperature of the switching element.
 8. Thegenerator-motor apparatus according to claim 4, wherein the multi-phaseswitching element group controls an electric current supplied to thestator such that the motor outputs predetermined torque when an internalcombustion engine is ignited, and the motor outputs the predeterminedtorque, and transmits the predetermined torque to the internalcombustion engine via a belt.
 9. The generator-motor apparatus accordingto claim 4, further comprising: a control circuit which controls themulti-phase switching element group; and a temperature sensor which isarranged on one of the first electrode plate and the second electrodeplate, and which detects an ambient temperature of the electrode plateon which the temperature sensor is arranged, wherein the control circuitdetects a temperature of the switching element based on the ambienttemperature actually detected by the temperature sensor.
 10. Thegenerator-motor apparatus according to claim 9, wherein the controlcircuit stores a map showing a relationship between the ambienttemperature and the temperature of the switching element, and detectsthe temperature of the switching element by extracting the temperatureof the switching element corresponding to the ambient temperatureactually detected by the temperature sensor using the map.
 11. A drivesystem, comprising: a generator-motor apparatus which starts an internalcombustion engine, and which generates electric power using enginetorque; and a control device which controls the generator-motorapparatus, wherein the generator-motor apparatus includes a motor thatincludes a rotor and a stator, and that serves as an electric powergenerator and an electric motor, a first electrode plate and a secondelectrode plate that are arranged on an end surface of the motor, andformed in a substantial horseshoe shape so as to surround a rotatingshaft of the motor, and a multi-phase switching element group thatcontrols an electric current supplied to the stator; the number of themulti-phase switching element groups corresponds to the number of phasesof the motor; each multi-phase switching element group includes aplurality of arms each of which includes a first switching device and asecond switching device that are electrically connected to each other inseries between the first electrode plate and the second electrode plate;a plurality of the first switching devices is directly attached to thefirst electrode plate; a plurality of the second switching devices isdirectly attached to the second electrode plate; each of the pluralityof the first switching devices and the second switching devices includesa first electrode, a second electrode, a switching element electricallyconnected to the first electrode and the second electrode and sandwichedbetween the first electrode and the second electrode, and a sealingmember which is provided around the switching element and which contactsthe first electrode and the second electrode; and the control deviceoutputs a signal for prohibiting an automatic stop of the internalcombustion engine to an internal combustion engine control device forcontrolling the internal combustion engine, when a temperature of theswitching element is higher than a predetermined temperature.
 12. Adrive system, comprising: a generator-motor apparatus which starts aninternal combustion engine, and which generates electric power usingengine torque; and a control device which controls the generator-motorapparatus, wherein the generator-motor apparatus includes a motor thatincludes a rotor and a stator, and that serves as an electric powergenerator and an electric motor, a first electrode plate and a secondelectrode plate that are arranged on the end surface of the motor, andformed in a substantial horseshoe shape so as to surround a rotatingshaft of the motor, and a multi-phase switching element group thatcontrols an electric current supplied to the stator; the number of themulti-phase switching element groups corresponds to the number of phasesof the motor; each multi-phase switching element group includes aplurality of arms each of which includes a first switching device and asecond switching device that are electrically connected to each other inseries between the first electrode plate and the second electrode plate;a plurality of the first switching devices is directly attached to thefirst electrode plate; a plurality of the second switching devices isdirectly attached to the second electrode plate; each of the first andsecond switching-devices includes a first electrode, a second electrode,a switching element electrically connected to the first electrode andthe second electrode and sandwiched between the first electrode and thesecond electrode, and a sealing member which is provided around theswitching element and which contacts the first electrode and the secondelectrode; and the control device controls an amount of electric powergenerated by the motor such that a temperature of the switching elementbecomes a temperature at which starting of the internal combustionengine is permitted.
 13. A computer-readable recording medium on which aprogram for directing a computer to perform control of a generator-motorapparatus for starting an internal combustion engine is recorded,wherein the generator-motor apparatus includes a motor which includes arotor and a stator, and which serves as an electric power generator andan electric motor, a first electrode plate and a second electrode platewhich are arranged on the end surface of the motor, and are formed in asubstantial horseshoe shape so as to surround a rotating shaft of themotor, and a multi-phase switching element group which controls anelectric current supplied to the stator; the number of the multi-phaseswitching element groups corresponds to the number of phases of themotor; each multi-phase switching element group includes a plurality ofarms each of which includes a first switching device and a secondswitching device that are electrically connected to each other in seriesbetween the first electrode plate and the second electrode plate; aplurality of the first switching devices is directly attached to thefirst electrode plate; a plurality of the second switching devices isdirectly attached to the second electrode plate; each of the pluralityof the first switching devices and the second switching devices includesa first electrode, a second electrode, a switching element electricallyconnected to the first electrode and the second electrode and sandwichedbetween the first electrode and the second electrode, and a sealingmember which is provided around the switching element and which contactsthe first electrode and the second electrode; and the program directsthe computer to perform a first step for detecting a temperature of theswitching element when the motor generates electric power, a second stepfor determining whether the detected temperature of the switchingelement is higher than a first reference value, and a third step forprohibiting an automatic stop of the internal combustion engine when thetemperature of the switching element is higher than the first referencevalue.
 14. The recording medium according to claim 13, wherein therecording medium stores the program for directing the computer tofurther perform a fourth step for detecting a remaining capacity of abattery, a fifth step for determining whether the temperature of theswitching element is higher than a second reference value when thetemperature of the switching element is equal to or lower than the firstreference value, a sixth step for determining whether the remainingcapacity of the battery is larger than a reference capacity when thetemperature of the switching element is higher than the second referencevalue, and a seventh step for limiting an amount of electric powergenerated by the motor such that the temperature of the switchingelement becomes equal to or lower than the second reference value whenthe remaining capacity of the battery is larger than the referencecapacity.
 15. The recording medium according to claim 13, wherein therecording medium stores the program for directing the computer tofurther perform an eighth step for lighting an alarm light when theremaining capacity of the battery does not increase even if apredetermined time has elapsed since the motor starts electric powergeneration.